1. Field of the Invention
The present disclosure relates to biomedical implants comprising surface-modified ceramic particles and biodegradable stereo complex polymers, its use for suppressing inflammation and improvement of mechanical property, and preparation method thereof.
2. Background of the Invention
Recently, due to development of the medical technology, biomedical implants acting as artificial organs or implantation materials have been used to substitute or recover damaged organs within human body. Applications of the biomedical implants have been gradually broadened, and thus, the researches into development of biomedical implants have been widely conducted. Materials used for preparing the biomedical implants include polymers, metals, ceramics, and composite materials. However, the material to be used in vivo must have biocompatibility with the host, and needs to have blood compatibility when exposed to blood, and needs to have tissue compatibility when exposed to biological tissues or cells, which places a limitation on available biomedical materials that can be utilized.
Thus, polymer materials having excellent formability and stable physical properties as well as being harmless to human body have been highlighted. In particular, because biodegradable polymers can minimize foreign body reaction caused by an immunological reaction developed when the biomedical implants are applied in vivo, due to their characteristics that they are degraded after a certain period of time.
However, biodegradable polymers have certain demerits, such as their physical properties being relatively poor compared with other polymers, and that when they are biodegraded, acidic materials such as lactic acid, glycolic acid, hydroxy caproic acid, maleic acid, phosphagen, hydroxy butyrate, hydroxyethoxy acetic acid, sebacic acid, alcohols, trimethylene glycol, amino acids, formalin, and alkylcyanoacrylate are generated, which cause inflammation reactions and cytotoxicity within human body.
Despite the shortcomings as mentioned above, biodegradable polymers have been widely used for biomedical implants owing to their characteristics of complete degradation after the lapse of a certain period of time. In addition, some methods to address to alleviate inflammation reactions resulting from biodegradable polymers usage have also been a suggested below.
For example, researches for finding an inflammation suppressing effect and improving physical properties by making biodegradable polymers used as implants have led to the use of contain non-steroidal anti-inflammatory drugs in ester series, such as salicylic acid and acetylsalicylic acid, had been conducted (J. Mater. Sci. Mater. Med., 13, pp. 1051-1055, 2002) and use of a method for suppressing both inflammation and restenosis by coating pyridoxal-5-phosphate on a stent has been suggested (WO 2006/056038).
In addition, a method for suppressing cell inflammation by making COX-2 protein and iNOS protein expressed with taheebo extract was suggested (KR 10-2008-0092263A) and a method to induce suppression of nitric oxide generation, as a byproduct of an inflammatory reaction, with gold and silver nano-particles have also been studied (KR 10-2009-0080855A).
However, one concern in regard to the above mentioned methods to suppress the already induced inflammations, which by contain an anti-inflammatory drug in biomaterials, in the risk of side effects due to the use of drugs.
Furthermore, any method to suppress the fundamental generation of acidic byproducts resulting from the degradation of biodegradable polymers has not yet been suggested. Namely, cellular inflammation, due to low pH of the acidic byproducts, have been constantly induced by the biodegradation of biodegradable polymers, but no fundamental solution thereto has been suggested, and there is a limitation on improvement of physical and mechanical properties of the biodegradable polymers.